I can't seem to get Winamp 5.33 to read the album artist tag in flac files.

I'm trying to use "Various Artists" as the album artist tag for compilations. I've tried setting "ALBUM ARTIST", "ALBUMARTIST" and "ENSEMBLE" tags to "Various Artists", but Winamp always seems to disply the value of "ARTIST" instead. What tag name is Winamp actually looking for?

Am I doing something wrong or is Album Artist just not working properly for flac files?

You can edit the Album Artist field via the Media Library, but it will only be added to the ml database and not written to the FLAC metadata.

We hope to address this problem in a future release (the sooner the better, imo).
Hopefully, the FLAC editor will eventually look a lot more like the Vorbis Editor (where extra/special/hidden fields are recognized and can be added/edited).

ps. yes, the correct Vorbis Comment style field for Album Artist is:
ALBUMARTIST=

Nullsoft FLAC Decoder v3.1 (in_flac.dll) in Winamp 5.666 definitely supports reading of all "ALBUM ARTIST", "ALBUMARTIST" and "ENSEMBLE" for Album Artist, writing to ALBUM ARTIST field, and includes an Album Artist field in the tag editor.